JP2016188905A - Head-mounted display device and method for manufacturing a volume holographic element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head-mounted display device in which designing property can be improved by improving the configuration of a volume holographic element, and a method for manufacturing a volume holographic element to be used for the above display device.SOLUTION: A head-mounted display device 100 includes: an image light emitting device 56a for the right eye, which uses laser light as a light source; a volume holographic element 1a for the right eye, which deflects image light L0a emitted from the image light emitting device 56a for the right eye; an image light emitting device 56b for the left eye, which uses laser light as a light source; and a volume holographic element 1b for the left eye, which deflects image light L0b emitted from the image light emitting device 56b for the left eye. In the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye, a curved portion 1u is symmetric in a vertical direction X, in which a radius of curvature in a center portion in a lateral direction Y is smaller than a radius of curvature in a side close to an observer's nose.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a head-mounted display device and a method for manufacturing a volume holographic element used in a head-mounted display device.

  As shown in FIG. 7A, the head-mounted display device includes an image light emitting device 56 and a deflecting device that deflects the image light emitted from the image light emitting device 56 and enters the eye E of the observer M. The image light emitting device 56 and the deflection member 53 are mounted on the head M0 of the observer M via a frame (not shown). Further, as shown in FIG. 7B, the deflection member 53 is a volume holo having a cross-sectional shape in which the radius of curvature (cross-sectional curvature deformation) increases in the lateral direction from the nose F side of the observer M toward the ear H side. A graphic element 1 has been proposed (see Patent Document 1). According to the volume holographic element 1 having such a configuration, a spot diameter of about 400 μm can be realized.

Japanese Patent No. 5,408,057

  However, when the volume holographic element 1 described in Patent Document 1 is used, the radius of curvature of the portion located on the nose F side of the observer M in the volume holographic element 1 is small, and therefore, as shown in FIG. In addition, the volume holographic element 1 is arranged in a posture that is largely inclined so that the end on the ear H side of the volume holographic element 1 is located in front of the end on the nose F side. For this reason, since the head-mounted display device has a structure in which the ear H side protrudes greatly forward from the nose F side, there is a problem that the design of the head-mounted display device is impaired.

  In view of the above problems, an object of the present invention is used in a head-mounted display device and a head-mounted display device that can improve the design by improving the configuration of a volume holographic element. The object is to provide a method of manufacturing a volume holographic element.

  In order to solve the above-described problems, one aspect of the head-mounted display device according to the present invention emits a right-eye image light emitting device that uses laser light as a light source and the right-eye image light emitting device. A right-eye volume holographic element that deflects image light to enter the right eye of the observer, a left-eye image light emitting device that uses laser light as a light source, and the left-eye image light emitting device that is emitted from the left-eye image light emitting device Left-eye volume holographic element that deflects image light and enters the left eye of the observer, right-eye image light emitting device, right-eye volume holographic element, and left-eye image light emitting device And a frame that holds the left-eye volume holographic element and is attached to the observer's head, wherein the right-eye volume holographic element and the left-eye volume holographic element are each The observer The curved portion has a cross-sectional shape that is line-symmetric in the vertical direction and that has a radius of curvature at the central portion in the lateral direction that is smaller than the radius of curvature at the nose side of the observer. It is characterized by.

  In the present invention, the right-eye volume holographic element and the left-eye volume holographic element each have a cross-sectional shape that is line-symmetric in the vertical direction. The same volume holographic element can be used for the graphic element. Each of the volume holographic element for the right eye and the volume holographic element for the left eye has a curved portion with a concave curved surface facing the observer side, and the curved portion has a curvature radius at the central portion in the lateral direction. The cross-sectional shape is smaller than the radius of curvature of the nose side. For this reason, the nose side part of the volume holographic element for right eyes and the volume holographic element for left eyes can be arrange | positioned in the position far from an observer's eyes. Therefore, it is not necessary to dispose the right-eye volume holographic element and the left-eye volume holographic element in a largely inclined posture so that the ear-side end portion is positioned forward. Therefore, the head-mounted display device does not have a structure in which the ear side protrudes more forward than the nose side, so that the design of the head-mounted display device can be improved.

  In the head-mounted display device according to the present invention, each of the right-eye volume holographic element and the left-eye volume holographic element has a first imaginary line connecting lateral ends of the right eye and the left eye. A posture parallel to the second imaginary line connecting the eyes, or a posture inclined such that an interval between the first imaginary line and the second imaginary line is narrower on the observer's ear side than the observer's nose side. And is preferably held by the frame. According to such a configuration, the ear-side end portions of the right-eye volume holographic element and the left-eye volume holographic element can be disposed rearward, so that in the head-mounted display device, the ear side is closer to the nose side. There is no need to protrude forward. Therefore, the design of the head-mounted display device can be improved.

  In the head-mounted display device according to the present invention, each of the right-eye volume holographic element and the left-eye volume holographic element is provided on the first surface of the first substrate and the first substrate. A layered holographic material layer, and each of the right-eye volume holographic element and the left-eye volume holographic element has a curvature radius of the curved portion defined by a shape of the first substrate. It is preferable. According to this configuration, the right-eye volume holographic element and the left-eye volume holographic element can be surely formed into a predetermined shape.

  In the head-mounted display device according to the present invention, each of the right-eye volume holographic element and the left-eye volume holographic element is laminated on the opposite side of the first substrate with respect to the holographic material layer. The right-eye volume holographic element and the left-eye volume holographic element each have a curvature radius of the curved portion of the shape of the first substrate and the second substrate. Is preferably defined by: According to this configuration, the right-eye volume holographic element and the left-eye volume holographic element can be surely formed into a predetermined shape.

  In the present invention, the first antireflection layer laminated on the first outer surface side, which is the surface opposite to the holographic material layer of the first substrate, and the holographic material layer of the second substrate are opposite to each other. It is preferable to have the 2nd antireflection layer laminated on the 2nd outer surface side which consists of a side surface. According to this configuration, when performing interference exposure in the manufacturing process of the first holographic element and the second holographic element, the exposure light is less likely to be reflected obliquely. Accordingly, it is possible to suppress the generation of interference fringes other than the predetermined position of the holographic material layer, and thus it is possible to suppress a decrease in diffraction characteristics due to extra interference fringes (extra diffraction grating).

  In the head-mounted display device according to the present invention, each of the right-eye volume holographic element and the left-eye volume holographic element has a radius of curvature of the central portion larger than that of the observer's ear. An aspect having a cross-sectional shape can be employed.

  In the head-mounted display device according to the present invention, the volume holographic element for the right eye and the volume holographic element for the left eye each have a cross-sectional shape extending linearly in the vertical direction. Can be adopted.

  In the head-mounted display device according to the present invention, each of the right-eye volume holographic element and the left-eye volume holographic element has a radius of curvature of the central portion smaller than that of the observer's ear. You may employ | adopt the aspect which has a cross-sectional shape.

  In the head-mounted display device according to the present invention, the volume holographic element for the right eye and the volume holographic element for the left eye each have a cross-sectional shape that is curved symmetrically in the vertical direction. May be.

  The present invention relates to a right-eye image light emitting device using laser light as a light source, and a right-eye volume hologram that deflects image light emitted from the right-eye image light emitting device and enters the right eye of an observer. A graphic element, a left-eye image light emitting device using laser light as a light source, and a right-eye volume that deflects image light emitted from the left-eye image light emitting device and enters the right eye of the observer Holding the holographic element, the right-eye image light emitting device, the right-eye volume holographic element, the left-eye image light emitting device, and the right-eye volume holographic element, and the observer's head In a method for manufacturing a volume holographic element used for the volume holographic element for the right eye and the volume holographic element for the left eye, Each of the right-eye volume holographic element and the left-eye volume holographic element has a curved portion with a concave curved surface facing the observer side, and the curved portion is line-symmetric in the vertical direction and laterally In the interference exposure step for the laminated body for manufacturing the volume holographic element, the radius of curvature of the central portion has a cross-sectional shape smaller than the radius of curvature of the observer's nose side. The volume holographic element is irradiated with a spherical wave of object light from the concave curved side, and the volume holographic element is projected from the side of the volume holographic element that is convex on the opposite side of the concave curved surface. Reference light composed of spherical waves is emitted from a direction inclined toward an end side of the element arranged on the nose side of the observer.

  In the method for manufacturing a volume holographic element according to the present invention, the step of manufacturing the right-eye volume holographic element and the step of manufacturing the left-eye volume holographic element use the laminate having the same configuration. In the interference exposure step for the laminate for manufacturing the right-eye volume holographic element and the interference exposure step for the stack for manufacturing the left-eye volume holographic element, the interference It is preferable that the direction in which the stacked body is arranged in the exposure apparatus is inverted upside down. According to this structure, the volume holographic element for right eyes and the volume holographic element for left eyes can be manufactured from the laminated body of the same structure by inverting the laminated body upside down.

  In the volume holographic element manufacturing method according to the present invention, the volume holographic element includes a translucent first substrate, a holographic material layer laminated on one surface side of the first substrate, and the holographic material. It is preferable to have a translucent second substrate laminated on the side opposite to the first substrate with respect to the layer.

  In the method of manufacturing a volume holographic element according to the present invention, a first antireflection layer is laminated on a first outer surface side of the first substrate which is a surface opposite to the holographic material layer, and It is preferable that the interference exposure process is performed in a state where a second antireflection layer is laminated on the second outer surface side which is a surface opposite to the holographic material layer. According to this configuration, the exposure light is less likely to be reflected obliquely on the first outer surface of the first substrate and the second outer surface of the second substrate. Accordingly, it is possible to suppress the generation of interference fringes other than the predetermined position of the holographic material layer, and thus it is possible to suppress a decrease in diffraction characteristics due to extra interference fringes (extra diffraction grating).

It is explanatory drawing which shows the one aspect | mode of the head mounted display apparatus to which this invention is applied. It is explanatory drawing which shows typically the planar structure of the head mounted display apparatus to which this invention is applied. It is explanatory drawing of the volume holographic element which concerns on Embodiment 1 of this invention. It is explanatory drawing of the volume holographic element which concerns on Embodiment 2 of this invention. It is explanatory drawing which shows the manufacturing method of the volume holographic element which concerns on Embodiment 1, 2 of this invention. It is explanatory drawing of the exposure interference process of the volume holographic element which concerns on Embodiment 1, 2 of this invention. It is explanatory drawing of the conventional volume holographic element.

  Embodiments of the present invention will be described below. In the following description, common parts are described with the same reference numerals so that the correspondence with the configuration described with reference to FIG. 7 can be easily understood. In the following description, the vertical direction is the X direction, the horizontal direction is the Y direction, the front and rear direction is the Z direction, and X, Y, and Z are attached to the vertical direction, the horizontal direction, and the front and rear direction.

[Embodiment 1]
(Configuration example of display device)
FIG. 1 is an explanatory diagram showing an embodiment of a head-mounted display device 100 to which the present invention is applied. FIGS. 1A and 1B are diagrams showing an optical system of the head-mounted display device 100, respectively. FIG. 2 is an explanatory view showing an aspect and an explanatory view showing an aspect of the appearance of the head-mounted display device 100. FIG. 2 is an explanatory diagram schematically showing a planar configuration of the head-mounted display device 100 to which the present invention is applied.

  1A and 2, the head-mounted display device 100 includes a right-eye image light emitting device 56a that uses laser light as a light source and an image light L0a emitted from the right-eye image light emitting device 56a. Are deflected from the right eye Ea of the observer M, the left eye image light emitting device 56b using laser light as a light source, and the left eye image light emitting device 56b. A left-eye deflecting member 53b that deflects the image light L0b and makes it incident on the left eye Eb of the observer M.

  The right-eye deflection member 53a and the left-eye deflection member 53b are provided with volume holographic elements 1 (a right-eye volume holographic element 1a and a left-eye volume holographic element 1b), which will be described later.

  Since the image light emitting device for right eye 56a and the image light emitting device for left eye 56b have the same basic configuration, only the configuration of the image light emitting device for left eye 56b will be described. Description of 56a is omitted. As shown in FIG. 1A, the left-eye image light emitting device 56b scans a light source 51 that emits a light beam for displaying an image and a light beam emitted from the light source unit 51 to form an image. The scanning optical system 20 includes the scanning mirror 21 and the optical system 52 that emits the light beam L0 scanned by the scanning optical system 20 to the left-eye deflection member 53b. In this embodiment, in the optical system 52, the relay lens system 54 and the projection lens system 55 are sequentially arranged from the scanning optical system 20 toward the left eye deflection member 53b. For example, the relay lens system 54 includes two lenses 541 and 542.

  The light source unit 51 emits light source light before light modulation or light modulated light. In the present embodiment, the light source unit 51 is configured as a modulated light emitting unit that emits light that has been modulated. More specifically, the light source unit 51 uses, as a light source, a red laser element 511 (R) that emits red light (R), a green laser element 511 (G) that emits green light (G), and blue light. It has a blue laser element 511 (B) that emits light (B), and two half mirrors 512 and 513 that synthesize optical paths of these laser elements. The red laser element 511 (R), the green laser element 511 (G), and the blue laser element 511 (B) are modulated to light intensity corresponding to each dot of the image to be displayed under the control of the control unit 59. The emitted light beam is emitted.

  The scanning optical system 20 scans incident light in a first scanning direction A1 and a second scanning direction A2 that intersects the first scanning direction A1, and generates image light L0a. Therefore, in this embodiment, the image light generation device 70 is configured by the light source unit 51 and the scanning optical system 20.

  The light beam L0b emitted from the scanning optical system 20 of the image light generation device 70 is projected onto the left eye deflection member 53b via the relay lens system 54 and the projection lens system 55. The operation of the scanning optical system 20 is also performed under the control of the control unit 59. The scanning optical system 20 can be realized by, for example, a micromirror device formed by a MEMS (Micro Electro Mechanical Systems) technique using a silicon substrate or the like.

  In this embodiment, the head-mounted display device 100 is a retinal scanning projection display device, and is scanned by the scanning optical system 20 in the first scanning direction A1 and the second scanning that intersects the first scanning direction A1. The image light L0a scanned in the direction A2 is deflected by the deflecting surface 530 of the deflecting member 53 in the first incident direction C1 corresponding to the first scanning direction A1 and the second incident direction C2 corresponding to the second scanning direction A2. The Then, the image light L0a reaches the retina E2 via the pupil E1 of the left eye Eb, thereby causing the observer M to recognize the image.

  The right-eye image light emitting device 56a has the same basic configuration as the left-eye image light emitting device 56b. For this reason, the image light L0a emitted from the right-eye image light emitting device 56a is deflected by the deflection surface 530a of the right-eye deflection member 53a and enters the right eye Ea.

  In this embodiment, a volume holographic element 1 (a volume holographic element 1a for the right eye and a volume holographic element for the left eye) described later are provided on the deflection surface 530a of the right eye deflection member 53a and the deflection surface 530b of the left eye deflection member 53b. A graphic element 1b) is provided. The volume holographic element 1 is a partial reflection type diffractive optical element, and the right-eye deflection member 53a and the left-eye deflection member 53b are partial transmission reflective combiners. For this reason, since external light also enters the right eye Ea and the left eye Eb via the right-eye deflection member 53a and the left-eye deflection member 53b (combiner), the user forms the head-mounted display device 100. It is possible to recognize an image in which the image light L0a and the external light (background) are superimposed. That is, the head-mounted display device 100 is configured as a see-through retinal scanning projection device.

  A beam diameter enlarging element 58 is disposed in the optical system 52. The light beam diameter enlarging element 58 applies the light beam emitted from the scanning optical system 20 to the first expansion direction B1 corresponding to the first scanning direction A1 (first incident direction C1) and the second scanning direction A2 (second incident direction C2). ) In at least one of the second enlargement directions B2 corresponding to.

  When the head-mounted display device 100 configured as described above is configured as a see-through type head-mounted display (eyeglass display), the head-mounted display device 100 includes, for example, as shown in FIG. It is formed in a shape like glasses. Specifically, the head-mounted display device 100 has a frame that holds the right-eye image light emitting device 56a, the right-eye deflection member 53a, the left-eye image light emitting device 56b, and the left-eye deflection member 53b. 60, and the frame 60 is attached to the head M0 of the observer M. The frame 60 includes a front portion 61 that supports the right-eye deflection member 53a and the left-eye deflection member 53b. A right-eye image is provided on each of the right temple 62a and the left temple 62b of the frame 60. A light emitting device 56a and a left eye image light emitting device 56b are provided. The right temple 62a and the left temple 62b are provided with an optical unit 57 including the optical component described with reference to FIG. The optical unit 57 may be provided with all of the light source unit 51, the scanning optical system 20, the relay lens system 54, the light beam diameter expanding element 58, and the projection lens system 55, and the optical unit 57 includes the scanning optical system. 20, only the relay lens system 54, the beam diameter expanding element 58, and the projection lens system 55 may be provided, and the optical unit 57 and the light source unit 51 may be connected by an optical cable or the like. In this case, the right-eye image light emitting device 56a and the left-eye image light emitting device 56b provided in each of the right temple 62a and the left temple 62b of the frame 60 include the scanning optical system 20, the relay lens system 54, It comprises a beam diameter expanding element 58 and a projection lens system 55.

(Configuration of volume holographic element 1)
FIG. 3 is an explanatory diagram of the volume holographic element 1 according to Embodiment 1 of the present invention. FIGS. 3A, 3B, and 3C are plan views of the volume holographic element 1 and volume holographic elements. It is the cross-sectional view which cut | disconnected the graphic element 1 by the YZ plane, and explanatory drawing which showed the cross-sectional shape of the volume holographic element 1 by the curvature radius.

  3A and 3B, the volume holographic element 1 (the right-eye volume holographic element 1a and the left-eye volume holographic element 1b) used for the right-eye deflection member 53a and the left-eye deflection member 53b. ) Each have a translucent first substrate 5A and a holographic material layer 4 laminated on one surface side of the first substrate 5A. Further, each of the volume holographic elements 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) is transparently laminated on the holographic material layer 4 on the opposite side of the first substrate 5A. A second substrate 5B is provided. In the present embodiment, the first substrate 5A and the second substrate 5B have the same shape and define the planar shape of the volume holographic element 1. The first substrate 5A and the second substrate 5B are made of a plastic substrate or a glass substrate.

  The first substrate 5A and the second substrate 5B have a rectangular shape extending in the lateral direction Y, and the holographic material layer 4 is provided in a rectangular shape at the central portion 5e. One end portion 5f in the lateral direction Y of the first substrate 5A and the second substrate 5B is centered on a virtual center line X0 extending in the lateral direction Y through the center in the vertical X direction of the holographic material layer 4. Positioning holes 5f1 and 5f2 are formed at line symmetry positions. A virtual center line X0 extending in the horizontal direction Y through the center in the vertical X direction of the holographic material layer 4 is formed on the other end 5g in the horizontal direction Y of the first substrate 5A and the second substrate 5B. Positioning holes 5g1 and 5g2 are formed at line-symmetric positions with respect to. The positioning holes 5f1, 5f2, 5g1, and 5g2 are used for positioning when the volume holographic element 1 is manufactured. Further, positioning may be performed based on the outer shape of the volume holographic element 1 (the outer shape of the first substrate 5A and the second substrate 5B).

  The volume holographic element 1 configured as described above is used as the right-eye volume holographic element 1a and the left-eye volume holographic element 1b in the state shown in FIG. 4 may be used as a volume holographic element 1a for the right eye and a volume holographic element 1b for the left eye by cutting both sides in the lateral direction Y. In this embodiment, those obtained by cutting both sides in the lateral direction Y with respect to the holographic material layer 4 are used as the right-eye volume holographic element 1a and the left-eye volume holographic element 1b.

  Here, the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) bends in the front-rear direction Z and is concavely curved in the right eye Ea and the left eye Eb of the observer M, respectively. The curved portion 1u has a curved surface 1t that faces away from the concave curved surface 1s. In this embodiment, the entire region where the holographic material layer 4 is provided is the curved portion 1u. However, the bending portion 1u has a cross-sectional shape that extends linearly in the vertical direction X. For this reason, the entire volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) is configured to be symmetrical with respect to the center line X0.

  In the volume holographic element 1 of this embodiment (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye), the bending portion 1u has a radius of curvature in the lateral direction Y as shown in FIG. Has changed. Further, the radius of curvature in the horizontal direction Y changes as shown in FIG. 3C at any position in the vertical direction. As shown in FIG. 3C, the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) has a nose F of the observer M from the central portion Y0 in the lateral direction Y. The radius of curvature continuously increases toward the portion Y1 located on the side, and the radius of curvature of the central portion Y0 in the lateral direction Y is smaller than the radius of curvature of the portion Y1 located on the nose F side of the observer M. ing. That is, the volume holographic element 1a for the right eye has a radius of curvature that continuously increases from the central portion Y0 in the lateral direction Y toward the portion Y1 located on the nose F side of the observer M. The radius of curvature of the central portion Y0 is smaller than the radius of curvature of the portion Y1 located on the nose F side of the observer M. Further, the volume holographic element 1a for the left eye has a radius of curvature that continuously increases from the central portion Y0 in the lateral direction Y toward the portion Y1 located on the nose F side of the observer M. The radius of curvature of the central portion Y0 is smaller than the radius of curvature of the portion Y1 located on the nose F side of the observer M.

  Further, the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) is directed from the central portion Y0 in the lateral direction Y toward the portion Y2 located on the ear H side of the observer M. The radius of curvature continuously decreases, and the radius of curvature of the central portion Y0 in the lateral direction Y is larger than the radius of curvature of the portion Y2 located on the ear H side of the observer M. That is, the volume holographic element 1a for the right eye has a radius of curvature that continuously decreases from the central portion Y0 in the lateral direction Y toward the portion Y2 located on the right ear Ha side of the observer M. The radius of curvature of the central portion Y0 in Y is larger than the radius of curvature of the portion Y2 located on the right ear Ha side of the observer M. Further, the volume holographic element 1b for the left eye has a radius of curvature that continuously decreases from the central portion Y0 in the lateral direction Y toward the portion Y2 located on the left ear Hb side of the observer M. The radius of curvature of the central portion Y0 in Y is larger than the radius of curvature of the portion Y2 located on the left ear Hb side of the observer M.

(Main effects of this form)
Since the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) of the present embodiment has the above-described configuration, the spots incident on the right eye Ea and the left eye Eb The diameter can be reduced to 150 μm.

  Further, when the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) of the present embodiment is used, the portion Y1 located on the nose F side is observed as shown in FIG. It can arrange | position in the position far from a person's eyes. For this reason, it is necessary to arrange the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) in a largely inclined posture so that the end on the ear H side is positioned forward. Absent. For example, as shown in FIG. 2, the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) each includes a first imaginary line Ya connecting the ends in the lateral direction Y, The posture in which Yb is parallel to the second virtual line Ye connecting the right eye Ea and the left eye Eb, or the interval between the first virtual lines Ya, Yb and the second virtual line Ye is from the observer M's nose F side. It can be arranged in an inclined posture so as to become narrower on the M ear H side. Therefore, since the end portions 1ha and 1hb on the ear H side of the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) can be disposed rearward, In the type display device 100, it is not necessary to project the ear H side forward from the nose F side. Therefore, the design of the head-mounted display device 100 can be improved.

  Further, since the right-eye volume holographic element 1a and the left-eye volume holographic element 1b have a line-symmetric cross-sectional shape in the vertical direction X, the right-eye volume holographic element 1a and the left-eye volume holographic element 1a. The same volume holographic element 1 can be used for the holographic element 1b. Therefore, the cost of the head-mounted display device 100 can be reduced.

  Further, in the right-eye volume holographic element 1a and the left-eye volume holographic element 1b, the curvature radius of the curved portion 1u is defined by the shapes of the first substrate 5A and the second substrate 5B, respectively. For this reason, the curvature radius of the volume holographic element 1a for right eyes and the volume holographic element 1b for left eyes can be prescribed | regulated reliably.

[Embodiment 2]
FIG. 4 is an explanatory diagram of the volume holographic element 1 according to Embodiment 2 of the present invention. FIGS. 4 (a), (b), (c), and (d) are planes of the volume holographic element 1. FIG. 1 is a cross-sectional view of the volume holographic element 1 cut along a YZ plane, an explanatory view showing the cross-sectional shape of the volume holographic element 1 with a radius of curvature, and a cross-sectional shape at another position of the volume holographic element 1 It is explanatory drawing which showed by the curvature radius. Since the basic configuration of this embodiment is the same as that of Embodiment 1, the same reference numerals are given to common portions, and detailed descriptions thereof are omitted.

  4 (a) and 4 (b), also in this embodiment, the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) are each transparent, as in the first embodiment. It has a first optical substrate 5A and a holographic material layer 4 laminated on one surface side of the first substrate 5A. Further, each of the volume holographic elements 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) is transparently laminated on the holographic material layer 4 on the opposite side of the first substrate 5A. A second substrate 5B is provided. In the present embodiment, the first substrate 5A and the second substrate 5B have the same shape and define the planar shape of the volume holographic element 1.

  Also in this embodiment, as in the first embodiment, the first substrate 5A and the second substrate 5B have a rectangular shape extending in the lateral direction Y, and the holographic material layer 4 is provided in a rectangular shape at the central portion thereof. ing. At the ends on both sides in the lateral direction Y of the first substrate 5A and the second substrate 5B, a virtual center line X0 extending in the lateral direction Y through the center in the vertical X direction of the holographic material layer 4 is centered. Positioning holes 5f1, 5f2, 5g1, and 5g2 are formed at the line symmetrical positions. The positioning holes 5f1, 5f2, 5g1, and 5g2 are used for positioning when the volume holographic element 1 is manufactured. Further, positioning may be performed based on the outer shape of the volume holographic element 1 (the outer shape of the first substrate 5A and the second substrate 5B).

  The volume holographic element 1 configured as described above is used as the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye while maintaining the state shown in FIG. In some cases, the central portion in the lateral direction Y in which 4 is formed is divided from other portions and only the central portion is used as the right-eye volume holographic element 1a and the left-eye volume holographic element 1b. In this embodiment, the central portion in the lateral direction Y on which the holographic material layer 4 is formed is divided from other portions, and only the central portion is used as the right-eye volume holographic element 1a and the left-eye volume holographic element 1b. Used.

  Here, the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) bends in the front-rear direction Z and is concavely curved in the right eye Ea and the left eye Eb of the observer M, respectively. The curved portion 1u has a curved surface 1t that faces away from the concave curved surface 1s. In this embodiment, the entire region where the holographic material layer 4 is provided is the curved portion 1u.

  In the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye), the curved portion 1u has a radius of curvature that changes in the lateral direction Y, and is located at a position along the center line X0. The radius of curvature in the horizontal direction Y changes as shown in FIG. As shown in FIG. 4C, the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) has a nose F of the observer M from the central portion Y0 in the lateral direction Y. The radius of curvature continuously increases toward the portion Y1 located on the side, and the radius of curvature of the central portion Y0 in the lateral direction Y is smaller than the radius of curvature of the portion Y1 located on the nose F side of the observer M. ing.

  Further, the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) has an ear H of the observer M from the central portion Y0 in the lateral direction Y at a position along the center line X0. After the radius of curvature partially decreases toward the portion Y2 located on the side, the radius of curvature of the central portion Y0 in the lateral direction Y is positioned on the ear H side of the observer M. It is smaller than the radius of curvature of the portion Y2.

  Further, in the bending portion 1u, the curvature radii in the lateral direction Y at the positions X1 and X2 that are separated from the center line X0 by the same distance in the up and down direction X are both at the center line X0 as shown in FIG. It changes similarly to the radius of curvature in the lateral direction Y at the position along. Therefore, the bending portion 1u is configured to be line-symmetric with respect to the center line X0 in the vertical direction X.

  If the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) having such a configuration is used, the spot diameters incident on the right eye Ea and the left eye Eb can be reduced to 150 μm. .

  If the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) of the present embodiment is used, as shown in FIG. The portion Y1 located at can be arranged at a position far from the observer's eyes. For this reason, it is necessary to arrange the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) in a largely inclined posture so that the end on the ear H side is positioned forward. Absent. For example, in the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye), the first imaginary lines Ya and Yb connecting the ends in the lateral direction Y are respectively left and right. The posture parallel to the second virtual line Ye connecting the eye Eb or the interval between the first virtual lines Ya, Yb and the second virtual line Ye is narrower on the observer H's ear H side than on the observer's nose F side. It can be arranged in an inclined posture. Therefore, since the end portions 1ha and 1hb on the ear H side of the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) can be disposed rearward, In the type display device 100, it is not necessary to project the ear H side forward from the nose F side. Therefore, the design of the head-mounted display device 100 can be improved.

  Further, the bending portion 1u is configured to be symmetrical with respect to the center line X0 in the vertical direction X. Therefore, the same volume holographic element 1 can be used for the right-eye volume holographic element 1a and the left-eye volume holographic element 1b. Therefore, the cost of the head-mounted display device 100 can be reduced.

[Method for Manufacturing Volume Holographic Element 1]
FIG. 5 is an explanatory diagram showing a method for manufacturing the volume holographic element 1 according to the first and second embodiments of the present invention. FIG. 6 is an explanatory diagram of the exposure interference process of the volume holographic element 1 according to the first and second embodiments of the present invention, and FIGS. 6 (a), (b), and (c) are descriptions of the interference exposure apparatus. FIG. 2 is an explanatory diagram showing an incident direction of exposure light to the volume holographic element 1 and an explanatory diagram showing a relationship between an incident direction of exposure light to the volume holographic element 1 and a diffraction direction.

  In manufacturing the volume holographic element 1 according to Embodiments 1 and 2 of the present invention, as shown in FIG. 5 (a), one surface of the translucent film 3 is in an uncured state or a semi-cured state. A material sheet 9 on which a holographic material layer 4 and a protective sheet 8 are laminated is used. Here, when the volume holographic element 1 is configured as a partially reflective diffractive element, the holographic material layer 4 includes a silver salt emulsion, a photosensitive polymer, a photosensitive resist, and the like, and the holographic material layer before curing. 4 has adhesiveness. The film 3 is made of a plastic film such as polyethylene terephthalate, polycarbonate, or triacetyl cellulose.

  In this embodiment, first, in the stacking step, as shown in FIG. 5B, the protective sheet 8 is peeled from the material sheet 9 in a dark room. Next, as shown in FIG. 5C, the film 3 is attached to one surface of a translucent first substrate 5A made of a plastic substrate or a glass substrate through the holographic material layer 4.

  Next, a translucent adhesive layer 6 made of an adhesive, an adhesive sheet or the like is provided on the surface of the film 3 opposite to the holographic material layer 4 side. Next, as shown in FIG. 5D, a translucent second substrate 5 </ b> B made of a plastic substrate or a glass substrate is bonded to the film 3 with an adhesive layer 6. As a result, a laminated body 1r (a precursor of the volume holographic element 1) shown in FIG. 5D is formed, and in the laminated body 1r, the first substrate 5A and the second substrate 5B have a first The holographic material layer 4, the film 3, and the adhesive layer 6 are sequentially laminated from the substrate 5A side to the second substrate 5B side. Here, since the curved portion is formed on the first substrate 5A and the second substrate 5B, the holographic material layer 4, the adhesive layer 6 and the film 3 are also formed with the curved portion. Therefore, the curved part 1u is formed in the laminated body 1r. In addition, when the 1st board | substrate 5 and the 2nd board | substrate 5B consist of a plastic substrate, you may form the curved part 1u after forming the laminated body 1r.

  Next, in the interference exposure step, as shown in FIG. 6A, the laminated body 1r is placed on the vibration isolation table of the interference exposure apparatus 10, and after performing interference exposure on the laminated body 1r, UV irradiation or When heat treatment is performed to cure the holographic material layer 4, the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) is manufactured.

  In the interference exposure apparatus 10, white light is separated into red light LR, green light LG, and blue light LB by dichroic mirrors 11a and 11b, and then red light LR and green light LG by total reflection mirrors 12a, 12b, 12c, and 12d. And the blue light LB is guided. The red light LR is converted into red light LR for object light L1 and red light LR for reference light L2 by the half mirror 13a. The green light LG is converted into green light LG for object light L1 and green light LG for reference light L2 by the half mirror 13b. The blue light LB is converted into blue light LB for object light L1 and blue light LB for reference light L2 by the half mirror 13c. The red light LR, the green light LG, and the blue light LB for the object light L1 are converted into parallel beams by the lens systems 14r, 15r, 14g, 15g, 14b, and 15b, respectively, and then the total reflection mirror 16a and the dichroic mirror 16b. , 16c, and then, the laminated body 1r is irradiated through the condenser lens 16d. On the other hand, the red light LR, the green light LG, and the blue light LB for the reference light L2 are respectively converted into parallel light beams by the lens systems 17r, 18r, 17g, 18g, 17b, and 18b, and then the total reflection mirror 19a. And the dichroic mirrors 19b and 19c, and then irradiates the laminated body 1r through the condenser lens 19d.

  At that time, as shown in FIG. 6B, object light L1 composed of spherical waves is irradiated from the side of the laminated body 1r that is the concave curved surface 1s of the volume holographic element 1, and the object light L1 converges. After that, the laminate 1r is irradiated as divergent light. On the other hand, the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) is formed from the side of the laminate 1r that is the convex curved surface 1t of the volume holographic element 1. The reference light L2 consisting of spherical waves is irradiated from the direction inclined toward the end portions 1ha and 1hb arranged on the nose F side of the observer M. At that time, the reference light L2 is irradiated as convergent light that converges after passing through the laminate 1r.

  As a result, as shown in FIG. 6C, the reference light L2 is emitted toward the volume holographic element 1 (the right-eye volume holographic element 1a and the left-eye volume holographic element 1b). The light (image light L0a, L0b emitted from the image light emitting device for right eye 56a and the image light emitting device for light eye 56b) is volume holographic element 1 (volume holographic element for right eye and left eye). The light is diffracted by the volume holographic element 1b) and collected at the convergence position (right eye Ea and left eye Eb) of the reference light L2.

  In such a manufacturing method, the right-eye volume holographic element 1a and the left-eye volume holographic element 1b are line-symmetric in the vertical direction. Accordingly, the laminate 1r having the same configuration is used in the process of manufacturing the right-eye volume holographic element 1a and the process of manufacturing the left-eye volume holographic element 1b. Then, in the interference exposure process for the laminate 1r for manufacturing the right-eye volume holographic element 1a and the interference exposure process for the stack 1r for manufacturing the left-eye volume holographic element 1b, FIG. The direction in which the laminated body 1r is arranged is reversed upside down with respect to the interference exposure apparatus 10 shown in a). Therefore, the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye can be manufactured by changing the direction of the laminated body 1r having the same configuration, and therefore the volume holographic element 1a for the right eye and the left The manufacturing cost of the volumetric holographic element for eye 1b can be reduced.

  Here, the first antireflection layer 7B is laminated on the first outer surface 5A0 which is the surface opposite to the holographic material layer 4 of the first substrate 5A, and is opposite to the holographic material layer 4 of the second substrate 5B. It is preferable to perform the interference exposure process in a state where the second antireflection layer 7B is laminated on the second outer surface 5B0 side which is a side surface. According to this configuration, the volume holographic element 1 (the volume holographic element 1a for the right eye and the volume holographic element 1b for the left eye) has the first antireflection layer 7B on the first outer surface side 5A0 of the first substrate 5A. The second antireflection layer 7B is laminated on the second outer surface 5B0 side of the second substrate 5B.

  The formation process of the first antireflection layer 7A and the second antireflection layer 7B is performed, for example, after the stacked body 1r is formed in the stacking process and before the interference exposure process. Alternatively, the first antireflection layer 7A and the second antireflection layer 7B may be formed on the first substrate 5A and the second substrate 5B before the lamination step, and then the lamination step may be performed. Further, one of the first antireflection layer 7A and the second antireflection layer 7B may be formed before the stacking step, and the other of the first antireflection layer 7A and the second antireflection layer 7B may be formed after the stacking step. Good. In this embodiment, as shown in FIG. 5C, the first antireflection layer 7A and the second antireflection layer 7B are formed on the first substrate 5A and the second substrate 5B before the stacking step, and then A lamination process is performed.

  According to such a configuration, it is possible to suppress the occurrence of interference fringes other than the predetermined position of the holographic material layer 4, and thus it is possible to suppress a decrease in diffraction characteristics due to extra interference fringes (extra diffraction grating). be able to.

1. Volume holographic element, 1a, Volume holographic element for right eye, 1b, Volume holographic element for left eye, 1ha, 1hb, End of ear side, 1s, concave surface, 1r,. Laminated body, 1t ... convex surface, 1u ... curved part, 4 ... holographic material layer, 5A ... first substrate, 5A0 ... first outer surface, 5B ... second substrate, 6 ... adhesive layer, 7A..First antireflection layer, 7B..Second antireflection layer, 10..Interference exposure apparatus, 53..Deflection member, 53a..Right eye deflection member, 53b..Left eye deflection member, 56a ..Image light emitting device for right eye, 56b..Image light emitting device for left eye, 60..Frame 61.Front part, 62a, 62b.Temple 100..Head-mounted display device 511 (B) ... Laser element for blue, 511 (G) ... Laser for green Element, 511 (R) ··· Red laser element, 530a, 530b ··· Deflection surface, E ·· Eye, E1 ·· Pupil, E2 ·· Retina, Ea ·· Right eye, Eb ·· Left eye, G · -Nose, H ... Ear, Ha ... Right ear, Hb ... Left ear, L0a, L0b ... Image light, L1 ... Object light, L2 ... Reference light, M ... Observer, M0 ... Head Part, X ... up / down direction, Y ... lateral direction, Y0 ... central part in the lateral direction Y, Y1 ... part located on the nose side, Y2 ... part located on the ear side, Ya, Yb ... 1 virtual line, Ye ... second virtual line, Z ... front-back direction

Claims (13)

An image light emitting device for the right eye using a laser beam as a light source;
A volumetric holographic element for the right eye that deflects the image light emitted from the image light emitting device for the right eye to enter the right eye of the observer;
A left-eye image light emitting device using laser light as a light source;
A volumetric holographic element for the left eye that deflects the image light emitted from the image light emitting device for the left eye and enters the left eye of the observer;
The right-eye image light emitting device, the right-eye volume holographic element, the left-eye image light emitting device, and the left-eye volume holographic element are held and attached to the observer's head. Frame,
Have
The right-eye volume holographic element and the left-eye volume holographic element each have a curved portion with a concave curved surface facing the observer side,
The head-mounted display characterized in that the curved portion is line-symmetric in the vertical direction and has a cross-sectional shape in which the radius of curvature of the central portion in the lateral direction is smaller than the radius of curvature of the observer's nose side apparatus. The head-mounted display device according to claim 1,
In each of the right-eye volume holographic element and the left-eye volume holographic element, a first imaginary line connecting lateral ends is parallel to a second imaginary line connecting the right eye and the left eye. Alternatively, the frame is held in an inclined posture so that an interval between the first virtual line and the second virtual line is narrower on the observer's ear side than on the observer's nose side. Head-mounted display device. The head-mounted display device according to claim 1 or 2,
The right-eye volume holographic element and the left-eye volume holographic element each have a translucent first substrate and a holographic material layer laminated on one surface side of the first substrate,
The head-mounted display device, wherein each of the right-eye volume holographic element and the left-eye volume holographic element has a curvature radius defined by the shape of the first substrate. The head-mounted display device according to claim 3,
The right-eye volume holographic element and the left-eye volume holographic element each have a translucent second substrate laminated on the opposite side of the first substrate with respect to the holographic material layer,
The right-eye volume holographic element and the left-eye volume holographic element each have a curvature radius of the curved portion defined by the shapes of the first substrate and the second substrate. Wearable display device. The head-mounted display device according to claim 4,
A first antireflection layer laminated on the first outer surface side of the surface of the first substrate opposite to the holographic material layer;
A second antireflection layer laminated on the second outer surface side of the surface of the second substrate opposite to the holographic material layer;
A head-mounted display device characterized by comprising: The head-mounted display device according to any one of claims 1 to 5,
The right-eye volume holographic element and the left-eye volume holographic element each have a cross-sectional shape in which the radius of curvature of the central portion is larger than the radius of curvature of the observer's ear side. Head-mounted display device. The head-mounted display device according to claim 6,
The head-mounted display device, wherein each of the right-eye volume holographic element and the left-eye volume holographic element has a cross-sectional shape extending linearly in the vertical direction. The head-mounted display device according to any one of claims 1 to 5,
The right-eye volume holographic element and the left-eye volume holographic element each have a cross-sectional shape in which the radius of curvature of the central portion is smaller than the radius of curvature of the observer's ear side. Head-mounted display device. The head-mounted display device according to claim 8,
The head-mounted display device, wherein each of the right-eye volume holographic element and the left-eye volume holographic element has a cross-sectional shape curved in line symmetry in the vertical direction. A right-eye image light emitting device using a laser beam as a light source, and a right-eye volume holographic element that deflects image light emitted from the right-eye image light emitting device and enters the right eye of an observer; A left-eye image light emitting device using laser light as a light source, and a right-eye volume holographic element that deflects image light emitted from the left-eye image light emitting device and enters the right eye of the observer The right-eye image light emitting device, the right-eye volume holographic element, the left-eye image light emitting device, and the right-eye volume holographic element are held and attached to the observer's head. In a method for manufacturing a volume holographic element used in the volume holographic element for the right eye and the volume holographic element for the left eye in a head-mounted display device having a frame,
The right-eye volume holographic element and the left-eye volume holographic element each have a curved portion with a concave curved surface facing the observer side,
The curved portion has a cross-sectional shape that is line-symmetric in the vertical direction and has a radius of curvature of a central portion in the lateral direction that is smaller than the radius of curvature of the observer's nose side;
In the interference exposure process for the laminate for manufacturing the volume holographic element, the interference exposure apparatus irradiates the volume holographic element with object light comprising a spherical wave from the concave surface side of the volume holographic element. A reference light comprising a spherical wave from a direction inclined to an end side of the volume holographic element arranged on the nose side of the observer from the side of the graphic element opposite to the concave curved surface. The volume holographic element manufacturing method characterized by irradiating. The method of manufacturing a volume holographic element according to claim 10,
In the step of manufacturing the right-eye volume holographic element and the step of manufacturing the left-eye volume holographic element, the laminate having the same configuration is used,
In the interference exposure step for the laminate for manufacturing the right-eye volume holographic element and the interference exposure step for the stack for manufacturing the left-eye volume holographic element, the interference exposure is performed. A method for producing a volume holographic element, characterized in that the orientation in which the laminate is arranged in the apparatus is inverted upside down. In the manufacturing method of the volume holographic element according to claim 10 or 11,
The volume holographic element includes a light-transmitting first substrate, a holographic material layer stacked on one side of the first substrate, and a layer opposite to the first substrate with respect to the holographic material layer. And a translucent second substrate, wherein the volume holographic element is manufactured. The method of manufacturing a volume holographic element according to claim 12,
A first antireflection layer is laminated on a first outer surface side of the first substrate opposite to the holographic material layer, and the second substrate comprises a surface opposite to the holographic material layer. A method of manufacturing a volume holographic element, wherein the interference exposure step is performed in a state where a second antireflection layer is laminated on the second outer surface side.

Images